I agree in general with all you say, I to have cut bearing & nuts of as you describe with oxy act and as you say not that difficult.
It is noticeably more difficult with oxy / propane mix that we now use ( to avoid bottle rental charge)This i am sure is due to the less intense heat i.e. slower pre heat time, resulting more heat transfer across the joint and less temperature differential in the two components.This difference in temperature is the key I sure to the washing effect we see.
The temperature differential issue is the reason I would possibly disagree with the suggestion of using a lower temperature blow gun for the HATZ bearing removal trick.
The key to success is applying heat quickly so the race expands, but heat does not have time to transfer across the joint and heat the shaft, clearly if both expand it wont release.
The method used by my uncle on the HATZ crank was to clamp a center punch vertically in a vice to act as a center to turn the crank on. the crank was orientated so that the race to be removed would fall under gravity when free.
I was instructed to turn the crank at uniform speed of approx 1 rev every 2 seconds. when happy with shaft rotation he apply heat with a pre lighted oxy act welding torch, he specifically selected a large (size 25 ) nozzle.
To my surprise the race dropped free after just a couple of seconds ! absolutely no indication of discoloration from heat.
You are correct in saying that this manual is quite old, it was about 30 year ago that we rebuilt this engine. It then ran for many years with the reclaimed bearing.
My original comment on this was intended to be tong in cheek, but also point out that what would seem obvious is not always true.
Clearly I would not suggest any one re uses a bearing in the manner unless it was. a) as in this case recommended my the manufacture. b ) the technician knowledgeable in the procedure.
The cost of bearings has fallen over the years so I guess salvaging a bearing for reuse would never be an issue nowadays.
Cheers Aidan
p.s Craig
not sure the relevance of your last post, I only scanned the manual, I did not write it.!! But if you do want to know 5 minutes with Google will answer your question.
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